the need for 33 or 35 spline stub axles....

[Ben D]

Gidday fellahs,

 

At risk of repeating what was posted earlier in a R230 related thread, and backtracking over what may have already been covered in this excellent forum, I'd like to start a new thread on stub axles for ultra high performance work. In my trawling for information, I have found the moser/modern motorsports 27 spline 4340 stub axle to be the current hot part for Z rear ends. Can anyone provide information on the Z32 300ZXTT stub axles, whether these are bigger than 27 spline (I hope they are !) and whether they can be retrofitted into a Z31 or earlier 280 Z type rear ends. In my experience a 27 spline shaft is not strong enough, no matter what it is made from. What are the options and how can we remove this weak link from the rear end once and for all ? By my calculations there is room for a 33 or 35 spline axle based on a 35 mm (1.377 in) diameter shaft provided the custom companion flange is made to match the spline and allow people to use the strong Z31 300ZXT and Z32 300ZXTT half shafts. Is anyone manufacturing these and if not, why not ?

 

Fire away. I look forward to learning heaps...

 

Ben

[Guest JAMIE T]

 

You mean like this?

 

I agree with you that a high end copy of a stock part can only be margainally better than the one it's replacing. No doubt the Modern Motorsports stub is a fine piece. But, I think the ZXTT part is superior.

 

This is the prototype for my car. I'm using it to make the jig. I will post more information when I have them completed.

[Ben D]

 

You mean like this?

 

I agree with you that a high end copy of a stock part can only be margainally better than the one it's replacing. No doubt the Modern Motorsports stub is a fine piece. But' date=' I think the ZXTT part is superior.

 

This is the prototype for my car. I'm using it to make the jig. I will post more information when I have them completed.[/quote']

 

 

Jamie,

 

Thats the ZXTT hub ? Looks tough, how many splines and whats the diameter of that shaft ? Are those bolts just visible behind the flange used to mount it ? I wonder whether that bit can be retrofitted into a Z31 ZXT trailing arm. I assume your application is early Z ???

[Guest JAMIE T]

Yes, the ZXTT hub is very stout. Yes, mine is being set-up for an S30. The spline count on the inside of the hub is 32. I haven't measured the shaft diam. I don't really think it matters. To ME anyway. It's alot bigger and stronger than the stock S30 parts or ANYTHING that is commercialy available as a replacement. I may offer it as an option for high powered cars once the details are worked out. I'm not too familiar with the Z31 rear suspension. I'm sure something could be fabricated to allow you to use it.

[BlackBeaut]

Hi Jamie,

I've been thinking of adapting a 200SX rear hub to fit on to my 240Z, not quite as full on as your fab work as that's way out of my league.

 

Just wondering if I could be cheeky and ask if you could send me a couple of front and back pics of your Z strut and let me know a couple of dimensions to see if my idea is even conceivable. Lord knows when I'll actually get around to stripping my rear suspension down, hopefully not too long though!

 

Hope you don't mind that I've taken the liberty of borrowing from your pic to show the dimensions I think I need to know at this stage.

A and B are the distances between the bolt holes that hold the drum backing plate on, C is the outer diameter of the stub axle housing.

 

BTW are you going to be using the Z32 drum handbrake and caliper set up on your struts or do you have something else in mind?

 

Cheers,

Rob

[S15 200sx owner]

Hey guys, really like the look and sound of what you are doing here. Look forward to seeing how this thread develops and learning heaps from it!

 

As i think i'm going to need a serious rear end upgrade on my car, as i have a RB30DET & the strong R33 RB25DET 5 speed so its going to be the rear end (currently R180 & all stock bits) thats my weak link, I am new to zeds so this is going to be a very benificial thread,

 

Thanks & Nice work!

[Guest JAMIE T]

I really SHOULD use the internal ZXTT E-brake. But, I'm cheap, and they are expensive. Man, those Z32TT guys sure do think they have some valuable parts. I tried to buy just the hub part you see in my pic, they wanted to sell me the whole aluminum spindle with no brakes for $175-200. That was even after I told them that all I needed was the hub, not the spindle. My brother works at a local pic-n-pull that has two locations. I called and asked him to look for Q45's which share the same hub as the ZXTT, but not the aluminum spindle(iron on the Q45). About a week later he called and said he'd forgotten all about it and he finally remembered so he checked it out. Happens that there was a Q45 at the other location. SO, I immediatly make tracks to the location. I got them off and paid only $15 for the PAIR. Before I decided to go with the ZXTT hubs, I'd already bought Mustang Cobra drilled and slotted rotors for the rear and the Cobra calipers also. I'll measure the dimensions you asked for. I need to get over to the shop anyway to finish up the prototype to take to Mikelly's on the the 30th.

 

ALot of benefits will come from this excercise...

 

1st being, the hub is substantially stronger than the any commercially available replacement.

 

2nd being, you only need to buy shorter axle shafts from Moser($300).

 

3rd being, no need to buy billet axles($695), axle flange adapters($420).

 

4th being, if I'd had more forethought, I could have used the superior ZXTT brakes. I still might if I can sell my $600 rear brakes to a Cobra guy.

 

I'll check on the dimensions requested and get back yo you on that.

[Ben D]

Interesting info Jamie,

 

Forgive me if I ask a stupid question, but from what I gather from your message below is that you're planning to run a Z32 TT hub and half shaft in an early Z, - does this mean you need to run the R230 and custom shortened half shafts, or do the Moser axle shafts suit R200 on the inner CV and Z32 on the outer ???

 

S15 200sx owner, I can officially assure you that the R180 and, more specifically, the half shafts and stub axles associated with it, will definitely be the weak links in your drive train. In my 2800 lb car with manual trans, the R200 stock bits are good for 30 or 40 mid/low 10 sec quarters with a DOT slick on poor tracks 1.6 to 60 ft), proabably wouldn't last near as long on a sticky track, and from what I have seen of the R180's , they're good for low 11's only. Dunno how these equate to road racing , but for drags I have found the aforementioned parameters to be pretty close.

 

 

 

I really SHOULD use the internal ZXTT E-brake. But' date=' I'm cheap, and they are expensive. Man, those Z32TT guys sure do think they have some valuable parts. I tried to buy just the hub part you see in my pic, they wanted to sell me the whole aluminum spindle with no brakes for $175-200. That was even after I told them that all I needed was the hub, not the spindle. My brother works at a local pic-n-pull that has two locations. I called and asked him to look for Q45's which share the same hub as the ZXTT, but not the aluminum spindle(iron on the Q45). About a week later he called and said he'd forgotten all about it and he finally remembered so he checked it out. Happens that there was a Q45 at the other location. SO, I immediatly make tracks to the location. I got them off and paid only $15 for the PAIR. Before I decided to go with the ZXTT hubs, I'd already bought Mustang Cobra drilled and slotted rotors for the rear and the Cobra calipers also. I'll measure the dimensions you asked for. I need to get over to the shop anyway to finish up the prototype to take to Mikelly's on the the 30th.

 

ALot of benefits will come from this excercise...

 

1st being, the hub is substantially stronger than the any commercially available replacement.

 

2nd being, you only need to buy shorter axle shafts from Moser($300).

 

3rd being, no need to buy billet axles($695), axle flange adapters($420).

 

4th being, if I'd had more forethought, I could have used the superior ZXTT brakes. I still might if I can sell my $600 rear brakes to a Cobra guy.

 

I'll check on the dimensions requested and get back yo you on that.[/quote']

[S15 200sx owner]

Interesting info Jamie' date='

 

Forgive me if I ask a stupid question, but from what I gather from your message below is that you're planning to run a Z32 TT hub and half shaft in an early Z, - does this mean you need to run the R230 and custom shortened half shafts, or do the Moser axle shafts suit R200 on the inner CV and Z32 on the outer ???

 

S15 200sx owner, I can officially assure you that the R180 and, more specifically, the half shafts and stub axles associated with it, will definitely be the weak links in your drive train. In my 2800 lb car with manual trans, the R200 stock bits are good for 30 or 40 mid/low 10 sec quarters with a DOT slick on poor tracks 1.6 to 60 ft), proabably wouldn't last near as long on a sticky track, and from what I have seen of the R180's , they're good for low 11's only. Dunno how these equate to road racing , but for drags I have found the aforementioned parameters to be pretty close.[/quote']

 

Thanks Ben, appreciate the feedback, i wasnt planning on running the car with the new RB engine on the R180, the guy i brought the car off ran it with an L series engine, so was probably fine for him.

 

After being inspired here i'm now planning to try and put the complete Z32 TT rear end in my car, or do what Jamie is doing, That might be easier that fitting in the whole lot frame and all.

[Mikelly]

Ben, Jamie is running the 300ZXTT R230 rear.

 

Jamie, We're all looking forward to seeing what you whipped up on the 30th... Pete is salevating to get a rear control arm fabb'ed up.

 

Mike

[Guest JAMIE T]

Ben, Mike is correct. All of my rear drivetrain parts are from a 300ZXTT. They have the beefiest parts of all Nissan's I've ever heard of. Even stronger than the mighty Skyline GT-R. I will be using the ZXTT R230 diff with a ratio of 3.69. And, I'll be usingthe ZXTT inner and outer CV's in conjunction with custom short Moser axle shafts.

 

I plan on running full drag slicks. My car is a 240Z. The engine is an RB26DETT that is being treated to a full port and polish on the head, and Blitz 272 cams. HKS GT2540 turbo's, huge intercooler, R33 crank(helps with RPM), triple or twin disc clutch(haven't decided which), and stand-alone EFI. I'm shooting for 600ish whp. The transmission is an RB25DET 5 speed with an OS Giken close gear set. The driveshaft is a custom built unit that was originaly designed for the 300ZXTT, but is being shortened to fit the short S30 chassis. I'm looking for low 10's in the quarter. Might run better than that, but we'll have to see. It's not being set-up as a full drag race prepared car.

[Ben D]

Jamie,

 

Sounds like you're putting together a nice combo. I'm pretty sure that in an early Z what you have there will run into the 9's pretty easy, you'll simply end up adding boost until you do. My car is also a street car, though once they insist on the roll cage, harnesses and parachute etc., you don't tend to do too much street driving. I like using the IRS for drags, they provide good handling and are easy to tune once you work out a few tricks on how to control camber change (especially in the Z31 rear end set up my car has). I too prefer keeping the manual box and the IRS as its pure and keeps the character of the cars pretty much intact, rather than them becoming just another race car with a 4 link and auto trans. I run the RB25 DET box after breaking the output shafts from a few RB20 DET boxes. The 2.5 litre unit is certainly tough inside - do you know the ratios you have in that gear set ? Their stock 3.3 first gear seems Ok for drags with a 26 inch tall tyre and a 4.1 rear end. If I were you I'd run the twin plate clutch first then use the triple only if required, as besides being nicer for street use a bit of slip on the launch cushions the driveline a bit and also provides a better 60 ft with less chance of bogging in (especially with a 3.7 rear end).

 

I run an ET street and reckon with a slick on a sticky track you'll need every bit of the Z32 TT stuff in the stub axle area - though it looks like from their design they dispense with the bits I am breaking. The only thing I don't like about the R230 is the 3.7 ratio. If you have a lower number than a 3.3 first gear in your gearbox you'll find launching difficult I would think. For lots of drag racing, I think even the stock 32 spline Z32 shafts will eventually give up in stock form, but I guess the moser bits will be made from 4340 and therefore would be much stronger ? Sounds like I should get a hold of some Z32TT half shafts and have a look - can you provide the diameter of the shaft and splines for comparison with R200 ?

 

 

Ben' date=' Mike is correct. All of my rear drivetrain parts are from a 300ZXTT. They have the beefiest parts of all Nissan's I've ever heard of. Even stronger than the mighty Skyline GT-R. I will be using the ZXTT R230 diff with a ratio of 3.69. And, I'll be usingthe ZXTT inner and outer CV's in conjunction with custom short Moser axle shafts.

 

I plan on running full drag slicks. My car is a 240Z. The engine is an RB26DETT that is being treated to a full port and polish on the head, and Blitz 272 cams. HKS GT2540 turbo's, huge intercooler, R33 crank(helps with RPM), triple or twin disc clutch(haven't decided which), and stand-alone EFI. I'm shooting for 600ish whp. The transmission is an RB25DET 5 speed with an OS Giken close gear set. The driveshaft is a custom built unit that was originaly designed for the 300ZXTT, but is being shortened to fit the short S30 chassis. I'm looking for low 10's in the quarter. Might run better than that, but we'll have to see. It's not being set-up as a full drag race prepared car.[/quote']

[Guest JAMIE T]

Yeah, I don't know the ratio's of the OS Giken gear set. I know the '26 wants to rev. I won't know how it's going to run until it's put together. The 3.70 might not be the optimum ratio. I think the engine will want 4.10's or higher. I'll have wait and see. It'll still be fast enough to scare the crap out of any passengers, LOL.

[stony]

Higher gears will be nice. I had a 3.90 in mine originally and went to a 4.88 That just magnified the breakage issues in teh rear with the twin plate clutch.

 

Jamie you are in a part of teh market knowone else is in. if you could successfully make a strut that could house the z32dett axles or maybe gtr axles ( i believe they are the same) you could make some money. I wanted to try but i was at the point where i was going to have to redo my entire rearend and wanted to be for sure it was going to be indestructable.

 

BTW your lean rich knob is on the way today... SOrry took so long.

[stony]

BTW the 3.90s with 275x50x15s put me across the line at just about redline in 3 rd gear where the 4.88s got me into 5th gear!!!! I would guess 370s would be even worse. the stock ratios in the rear for the skyline GTSt where 4.363 so some where close to there would prabably be best.

[S15 200sx owner]

Hey Stony,

 

I am now looking at going back to my original plan of swapping into my 72 240z a mech LSD from a R32 GTR (think this will be a lot easier than the R230 after reading all this) you wouldnt happen to know the Ratio of these would you?

 

Also i wonder if the R32 GTR CV's are the same as the Z31 or the Z32TT ones so i could use some of Ross's CV adapters????

[Guest JAMIE T]

I want to see how this thing is gonna act with the 3.70's. I'm using a drag radial for now. It's a 285/35/18. I can't remember off hand the diam. I really don't have anything to compare it to.

[260DET]

There is a Japanese site where fitting Z31 rear stub axles to a S30 is shown with pics step by step. No link sorry.

 

What mischief are you up to now Ben, the S12 not good enough?

[stony]

i fit z 31 stubs in a s30 strut unfortunatley the outboard side of the stub is the same size as the s30 stub and is where they break. the solution is to fit a z32 axle. If this is completed, will greatly increase the strength of the rearend. and could be a good moneymaker if done right. Somehow take the S30 strut housing and mate it up to something that houses the z32 axles and bearing. then make custom length axles and BAMMM your done. I did that with the z31 stubs i wish i had done it with the Z32 stuff.

 

Basically i machined the housing to accept the Z31 bearings instead of the S30 bearing. the same or something similar should be able to be done with the z32 stuff.

[S15 200sx owner]

i fit z 31 stubs in a s30 strut unfortunatley the outboard side of the stub is the same size as the s30 stub and is where they break. the solution is to fit a z32 axle. If this is completed' date=' will greatly increase the strength of the rearend. and could be a good moneymaker if done right. Somehow take the S30 strut housing and mate it up to something that houses the z32 axles and bearing. then make custom length axles and BAMMM your done. I did that with the z31 stubs i wish i had done it with the Z32 stuff.

 

Basically i machined the housing to accept the Z31 bearings instead of the S30 bearing. the same or something similar should be able to be done with the z32 stuff.[/quote']

 

Thanks Stony, i am going to give the Z32TT stub axle conversion a crack! I will also look at the GTR stubs (i believe they are same as Z32TT)

 

Is there enough thickness of material in the S30 hub to machine to Z32TT bearing size??

 

Stony, any idea on the diff ratio of the R32 GTR??